Use Github workflow to build YNH package supporting custom path

[oleole39]

Problem

Custom path install not supported with current cinny_ynh version

Solution

Use github workflow to build a specific package supporting YNH custom path install.

1. Merge this PR on testing
2. A first release has to be created using workflow triggered on every push to testing branch. It will create a draft release at https://github.com/YunoHost-Apps/cinny_ynh/releases where sample versioning/text should be corrected and then published.
3. add path & SHA sum corresponding that that first release in the manifest
4. merge PR to master
5. you may want to disable manually the workflow triggered on every push to testing branch, to enable it only when needed. The main workflow is triggered everytime it detects a PR from yunohost-bot mentioning an upgrade available (based on manifest autoupdate's strategy).
6. For each new upgrade PR by yunohost-bot, BEFORE merging the latter, the draft release automatically created by the workflow will have to be published manually, and source ynh_build (URL and SHA sum) has to be replaced manually in the manifest.

PR Status

• [x] Code finished and ready to be reviewed/tested
• [x] The code base of the PR comes mostly from app it-tools_ynh where it seems to work properly:
  • [x] GH workflow when push on testing works fine
  • [x] install script working and app overall navigation was tested manually
  • [x] CI passed
  • [ ] GH workflow when pull request is yet to be tested (waiting for an upgrade from upstream...)
  • [ ] CI says it's fine, but I wonder whether path should be modified via scripting when changing URL, or restoring on a different path - to be checked
• [ ] Code for this app has been manually tested

Notes:

• Yunorunner on this PR will fail as long as there is no published release in this repo / linked to in the manifest.
• The build script added with this PR can be run locally and even generate draft Github release if a Github personal token is supplied